1. Field of the Invention
The present invention relates generally to a homogeneous hydrogenation process. More particularly, the invention relates to a homogeneous hydrogenation process comprising contacting a solution of a compound selected from the group consisting of monosaccharides, disaccharides, trisaccharides, polysaccharides, corn starch hydrolyzate, and compounds having the formula RH.sub.2 C--CO--CH.sub.2 R wherein R is hydroxyl or halogen with hydrogen in the presence of a catalyst comprising a ruthenium triphenyl phosphine complex and a strong acid.
2. Description of the Prior Art
The hydrogenation of a variety of organic compounds by contacting a solution of the compound with molecular hydrogen in the presence of a hydrogenation catalyst is well-known in the art. As is also well-known, hydrogenation processes are generally classifiable into one of two broad catagories, depending upon the physical phase in which the catalyst is present during the hydrogenation process. In the first type, referred to as a heterogeneous hydrogenation process, the catalyst is essentially insoluble in the reaction medium. By comparison, in the second type, referred to as a homogeneous hydrogenation process, the catalyst is essentially completely soluble in the reaction medium.
The use of ruthenium-containing materials as catalysts in both heterogeneous and homogeneous hydrogenation processes has also been reported. In U.S. Pat. No. 2,868,847 issued to Boyers, it is disclosed that ruthenium-containing catalysts may be utilized in a heterogeneous process for preparing hydrogenated derivatives of mono- and di-saccharides. In U.S. Pat. No. 3,454,644 issued to Dewhirst, a homogeneous hydrogenation process is disclosed utilizing a ruthenium or osmium metal complex as a catalyst and a high hydrogen pressure. Among the various ligands described as useful in said complexes are several tertiary phosphines, including triphenyl phosphine.
It is an object of the present invention to provide a homogeneous process for the preparation of hydrogenated derivatives of certain compounds containing an activated carbonyl group.